This could be a big one (forgiveness, friendship with God, life to the full, life forever, etc, etc, etc) but I've just been amazed at how people can choose to follow Jesus and not realise how amazing grace really is and that God's forgiveness is total, complete and permanent. If you think following Jesus means you still need to work hard to earn God's love and not lose his forgiveness, think again because it's much better than that! Am I making it up? No! It's all in the Bible if we want to go looking (and we should - especially if we say we follow Jesus)...
Ephesians 1:3-14
Ephesians 2:1-10
The passages above are an incredible list of all the amazing things God has given everyone who has put their trust in Jesus. Have a good read and try and take it all in! It's better than you think and it doesn't depend on you! There's nothing you can do to make God love you any more or any less than he does right now and if you've put your faith in Jesus, he's given you so much and it's a done deal! Jesus has saved you and there's no going back!
Loving that.